Effects that begin with the characters F\_ are effects that are part of the FFmpeg software
as opposed to those coded within the \CGG{} program. These are discussed separately in
\nameref{sec:ffmpeg_audio_video_plugins}.
-Effect plugins modify the track when played, according to how they are set, with no permanent storage of the output except when the project is rendered. There are many Plugins in \CGG{} Infinity which are actually quite easy to use just by experimenting with them. The plugins are shown and selected from the \textit{Resources window} (figure~\ref{fig:video-plugins}). They are described in more detail later.
+Effect plugins modify the track when played, according to how they are set, with no permanent storage of the output except when the project is rendered. There are many Plugins in \CGG{} Infinity which are actually quite easy to use just by experimenting with them.
+The plugins are shown and selected from the \textit{Resources window} (figure~\ref{fig:video-plugins}). They are described in more detail later.
\begin{figure}[htpb]
\centering
In \texttt{Settings$\rightarrow$ Preferences$\rightarrow$ Appearance} tab, there is a pulldown for \textit{Plugin icons} where the user can choose between the \textit{original} icons, \textit{regular} or \textit{smoother}, \textit{cinfinity}\protect\footnote{Cinfinity /2 icon set is credited to Sam - Creative Common By -- \url{https://creativhecommons.org/licenses/by/3.0/}} -- the default modernized set, or \textit{cinfinity2} (figure~\ref{fig:audio-plugins}).
-Note that when you change the plugin icons, your session will automatically save the backup, stop, restart, and reload (figure~\ref{fig:plugin-icons}).
-
\begin{figure}[htpb]
\centering
\includegraphics[width=0.6\linewidth]{audio-plugins.png}
\label{fig:audio-plugins}
\end{figure}
+Note that when you change the plugin icons, your session will automatically save the backup, stop, restart, and reload (figure~\ref{fig:plugin-icons}).
+
\begin{figure}[htpb]
\centering
\begin{tikzpicture}[scale=1, transform shape]
\textit{Realtime} effect plugins are listed in the Resources window as \textit{Audio} Effects and \textit{Video} Effects. Effect plugins are used by dragging them from the Resources window onto an audio track if it is an audio effect or video track if it is a video effect. You will see a colored bar \index{plugins!toolbar} appear beneath the track with the plugin name on it. If there is data on the destination track, the effect is applied to the entire track, unless a edit or a region of the track is selected (wipe selection or In/Out points) in which case the effect is pasted into that region only. If there is no data on the track or no selected region set, the effect is not added.
-Plugins are layered under the track they apply to. When dragging more than one effect onto an armed track, you will see the effects layering from \textit{top to bottom}, on the bottom of that track. When the track is played back, effects are processed from \textit{top to bottom}. The output of the top effect becomes the input of the bottom effect and so on. "The pipeline in Cinelerra's\protect\footnote{credit to Original Creator} plugin design is the \textit{pull} method. The rendering pipeline starts at the final output and the final steps in the rendering pipeline are reading the data from disk. Every step in the rendering chain involves requesting data from the previous step. When the rendering pipeline eventually requests data from a plugin chain, each plugin requests data from the plugin before it. This is less intuitive than the push method but is much more powerful. Realtime plugins written using the pull method can change the rate data is presented to the viewer and the direction of playback. The pull method allows plugins to take in data at a higher rate than they send it out." Side note: if you want to avoid the automatic \textit{top to bottom} application of plugins, you can take advantage of \textit{nested assets} to manipulate the order the plugins are applied (see \ref{sec:nesting_clips_and_assets}).
+Plugins are layered under the track they apply to in what is referred to as the effect bar. Do a double click on the effect bar to select the effect region. When dragging more than one effect onto an armed track, you will see the effects layering from \textit{top to bottom}, on the bottom of that track. When the track is played back, effects are processed from \textit{top to bottom}. The output of the top effect becomes the input of the bottom effect and so on. "The pipeline in Cinelerra's\protect\footnote{credit to Original Creator} plugin design is the \textit{pull} method. The rendering pipeline starts at the final output and the final steps in the rendering pipeline are reading the data from disk. Every step in the rendering chain involves requesting data from the previous step. When the rendering pipeline eventually requests data from a plugin chain, each plugin requests data from the plugin before it. This is less intuitive than the push method but is much more powerful. Realtime plugins written using the pull method can change the rate data is presented to the viewer and the direction of playback. The pull method allows plugins to take in data at a higher rate than they send it out." Side note: if you want to avoid the automatic \textit{top to bottom} application of plugins, you can take advantage of \textit{nested assets} to manipulate the order the plugins are applied (see \ref{sec:nesting_clips_and_assets}).
Instead of dragging from the Resources window, effects may be applied to a single armed track or a region via a popup menu. On the entire track or on a region determined by a selection wipe or by the In/Out points, right click and select \textit{Attach effect} \index{plugins!attch effect} from the popup. The attach effect dialog gives you more capability than just dragging and dropping. For example, the attach effect dialog lets you attach two more types of effects: \textit{shared effects} and \textit{shared tracks} which are explained in a later section. Select a plugin from the Plugins column and hit the green colored checkmark under the plugins column to attach it. The result is the same as if the effect was dragged from the Resources window.
One more method to apply an effect on all armed tracks of the same type (video or audio) is to use the \textit{Video} or \textit{Audio} pulldown \textit{Attach Effect} option. This brings up a menu which has a useful checkbox to \textit{Attach single standalone and share others} (see \ref{sec:shared_effect_tracks}). The default setting is checked on.
+
After attaching an effect to a track, it often needs to be configured. There are two ways to get to the configuration controls. Click on the magnifying glass \index{plugins!show controls} symbol on the right side of the effect bar -- this is the middle symbol on the bar as you can see in the picture below. Alternatively, you can right click on the effect bar to bring up the effect popup which has a \textit{Show} option. Either method causes the GUI for the effect to appear in a separate window. There will not be a popup if the plugin has no GUI.
\CGG{}’s default setup is in the file \texttt{\$CIN\_DAT/expan\-ders.txt} but if the user wants their own specific setup and if the file in \texttt{\$HOME/.\\bcast5/expanders.txt} exists, it will take precedence.
If there are recommendations for other relevant categories, they can be added. The subtree structure is applicable to any of the \textit{Video Effects/Transitions} or \textit{Audio Effects/Transitions}. You can not sort once an expansion is in effect (figure~\ref{fig:expander}).
-The \texttt{expanders.txt} file has very specific requirements. The most specific is that there are no blanks -- you must use tabs only. A \# (pound sign) can be used in column 1 to indicate a comment. A short example of what the txt file looks like is shown below.
-
\begin{figure}[htpb]
\centering
\includegraphics[width=0.8\linewidth]{expander.png}
\label{fig:expander}
\end{figure}
+The \texttt{expanders.txt} file has very specific requirements. The most specific is that there are no blanks -- you must use tabs only. A \# (pound sign) can be used in column 1 to indicate a comment. A short example of what the txt file looks like is shown below.
+
\begin{lstlisting}[style=sh]
Video Effects
-Favorites
\label{sub:live_audio}
\index{live audio}
-The Live Audio effect reads audio directly from the sound card input. It replaces any audio on the track so it is normally applied to an empty track. To use Live Audio, highlight a horizontal region of an audio track or define In and Out points. Then drop the Live Audio effect into it. Create extra tracks and attach shared copies of the first Live Audio effect to the other tracks to have extra channels recorded. Live Audio uses the sound driver selected in \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Playback A $\rightarrow$ Audio Out for recording}, but unlike recording it uses the playback buffer size as the recording buffer size and it uses the project sample rate as the sampling rate. These settings are critical since some sound drivers can not record in the same sized buffer they play back in.
+The Live Audio effect reads audio directly from the sound card input in real time. It replaces any audio on the track so it is normally applied to an empty track. To use Live Audio, highlight a horizontal region of an audio track or define In and Out points. Then drop the Live Audio effect into it. Create extra tracks and attach shared copies of the first Live Audio effect to the other tracks to have extra channels recorded. Live Audio uses the sound driver selected in \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Playback A $\rightarrow$ Audio Out for recording}, but unlike recording it uses the playback buffer size as the recording buffer size and it uses the project sample rate as the sampling rate. These settings are critical since some sound drivers can not record in the same sized buffer they play back in.
Live audio has been most reliable when ALSA is the recording driver and the playback fragment size is $2048$. Drop other effects after Live Audio to process sound card input in realtime. With live audio there is no read-ahead, so effects like compressor will either delay if they have read-ahead enabled or playback will under-run. A potential problem is that sometimes the recording clock on the sound card is slightly slower than the playback clock. The recording eventually falls behind and playback sounds choppy. Live Audio does not work in reverse.
\end{description}
\paragraph{Shading box:} The boxing option allows for calculating the inversion of the digital negatives in a given area of the frame as opposed to the entire frame. The program will automatically calculate the columns and rows to shave from the frame when compute negfix values is checked. A default box area is initially calculated, called the shaving box, based on where the min/max difference in a row/column is less than the program defined tolerance. This row/column minimum and maximum difference must be greater than 0.05. The effect is to cut away the border areas with constant color. If you check the Show active area, you can see the box in the compositor window. The boundary search is constrained to a range of 0.1 to 0.9 times the frame dimensions, to create a 10 percent shaved margin to avoid over-scan and negative edge bleeding. Manual adjustment of the shaving box is controlled via the four sliders on the bottom right which move each of the left, right, top and bottom shaving margins. The slider bar new values automatically take effect as you move the box and you will see the right-hand side applied values change. When you have either the rows or the columns where the minimum slider is greater than or equal to the maximum slider, the default box will be in effect instead.
-\paragraph{Optional postprocessing:} In order to have the values of Contrast and Brightness take effect, you must check the Postprocess checkbox.
-\begin{description}
- \item[Contrast] is the difference in brightness between objects or regions.
- \item[Brightness] refers to the overall lightness or darkness of the image.
-\end{description}
-
-Figure~\ref{fig:c41} shows the C41 controls on the left and part of the Compositor window with grid lines showing the default shading box since the Show active area box is checked. Changes have been made to the left-hand side original computed values as seen in the right-hand side such as Gamma G which contains the hairline cursor and has a partial red outline value box.
-
\begin{figure}[htpb]
\centering
\includegraphics[width=0.9\linewidth]{c41.png}
\label{fig:c41}
\end{figure}
+\paragraph{Optional postprocessing:} in order to have the values of Contrast and Brightness take effect, you must check the Postprocess checkbox.
+\begin{description}
+ \item[Contrast] is the difference in brightness between objects or regions.
+ \item[Brightness] refers to the overall lightness or darkness of the image.
+\end{description}
+
+Figure~\ref{fig:c41} shows the C41 controls on the left and part of the Compositor window with grid lines showing the default shading box since the Show active area box is checked. Changes have been made to the left-hand side original computed values as seen in the right-hand side such as Gamma G which contains the hairline cursor and has a partial red outline value box.
+
\subsection{Chroma Key}%
\label{sub:chroma_key}
\index{chroma key}
-This effect erases pixels which match the selected color. They are replaced with black if there is no alpha channel and transparency if there is an alpha channel. In this case, you create a matte in the alpha channel, which is not visible to us. The selection of color model is important to determine the behavior (figure~\ref{fig:chroma-key}).
+This effect erases pixels which match the selected color. They are replaced with black if there is no alpha channel and transparency if there is an alpha channel. In this case, you create a matte in the alpha channel, which is not visible to us. The selection of color model is important to determine the behavior (figure~\ref{fig:chroma-key}).
\begin{figure}[htpb]
\centering
\label{fig:chroma-key}
\end{figure}
-Chroma key uses either the \textit{lightness} or the \textit{hue} to determine what is erased. Use value singles out only the lightness to determine transparency (Luma Key).
-Select a center color to erase using the \textit{Color} button. Alternatively a color can be picked directly from the output frame by first using the \textit{color picker} in the compositor window and then selecting the \textit{Use color picker} button. This sets the chroma key color to the current color picker color.
+Chroma key uses either the lightness or the hue to determine what is erased. \textit{Use value} singles out only the lightness to determine transparency (Luma Key).
+
+\textit{Color section}
+
+Select a key color to erase using the \textit{Color} button. Alternatively a color can be picked directly from the output frame by first using the \textit{color picker} in the compositor window and then selecting the \textit{Use color picker} button. This sets the chroma key color to the current color picker color.
Be aware that the output of the chroma key is fed back to the compositor, so selecting a color again from the compositor will use the output of the chroma key effect. The chroma key should be disabled when selecting colors with the color picker.
-If the lightness or hue is within a certain \textit{threshold} it is erased. Increasing the threshold determines the range of colors to be erased. It is not a simple on/off switch. As the color approaches the edge of the threshold, it gradually gets erased if the \textit{slope} is high or is rapidly erased if the slope is low. The slope as defined here is the number of extra values flanking the threshold required to go from opaque to transparent.
+\textit{Key parameters section}
+
+If the lightness or hue is within a certain \textit{threshold} it is erased. Increasing the threshold determines the range of colors to be erased. It is not a simple on/off switch; it's a range color. As the color approaches the edge of the threshold, it gradually gets erased if the \textit{slope} is high or is rapidly erased if the slope is low. The slope as defined here is the number of extra values flanking the threshold required to go from opaque to transparent. The \textit{Default} button returns Threshold to the value $10.0$; Slope to the value $0.0$; and Color to black (\#ff000000). The \textit{Reset} button and the \textit{reset} icons next to the sliders always return to the value $0.0$. Before the sliders are the \textit{input boxes} so that the precise numerical values can be written.
Normally threshold is very low when using a high slope. The two parameters tend to be exclusive because slope fills in extra threshold. The slope tries to soften the edges of the chroma key but it does not work well for compressed sources. A popular softening technique is to use a maximum slope and chain a blur effect below the chroma key effect to blur just the alpha.
-\subsection[Chroma Key (HSV)]{Chroma Key (HSV)}%
-\label{sub:chroma_key_hsv}
-\index{chroma key HSV}
+\subsection[Chroma Key (Avid)]{Chroma Key (Avid)}%
+\label{sub:chroma_key_avid}
+\index{chroma key Avid}
-Chroma Key (HSV)\protect\footnote{Credit for Plugin by Jerome Cornet \url{http://jcornet.free.fr/linux/chromakey.html}} (figure~\ref{fig:chroma-key-hsv}) replaces a color with another color or transparency using HSV variables; it is frequently used to remove a color from a video to composite with another image. This process is generally referred to as green screen or blue screen process (because of the color that is keyed out). More information: {\small \url{http://en.wikipedia.org/wiki/Chromakey}}
+Chroma Key (Avid)\protect\footnote{Credit for Plugin by Jerome Cornet; credit to original creator for major upgrade and credit to SGE for adaption and imrovements.} (figure~\ref{fig:chroma-key-hsv-avid}) replaces a color with another color or transparency using HSV variables. It is frequently used to remove a color from a video to composite with another image. This process is generally referred to as green screen or blue screen process because of the background color that is keyed out. More information is at: {\small \url{http://en.wikipedia.org/wiki/Chromakey}}.
\begin{figure}[htpb]
- \centering
- \includegraphics[width=0.55\linewidth]{chroma-key-hsv.png}
- \caption{Keying a green screen with Chroma Key (HSV)}
- \label{fig:chroma-key-hsv}
+ \centering
+ \includegraphics[width=0.55\linewidth]{chroma_key_avid.png}
+ \caption{Windows config for Chroma Key (Avid/HSV)}
+ \label{fig:chroma-key-hsv-avid}
\end{figure}
\subsubsection*{Requirements}
\label{ssub:requirements}
-The subject in the movie should have a good background. The lighting is crucial and good lighting during production will save you time with much less effort than in post-production. Another tip is to use a low-compressed, intraframe codec with as high a color depth as possible. In case of YUV-type source signal, it is better to have subsampling $4:4.4$ or $4:2:2$.
-Here we assume that we have a good video, filmed on green (or blue) screen that we want to use. Important: Make sure you are using a color model that has an alpha channel, such as \textit{RGBA8}, \textit{RGBAFloat}, \textit{YUVA8}. To change color model, go to \texttt{Settings $\rightarrow$ Format $\rightarrow$ Color Model}.
+The subject in the timeline video should have a good background. The lighting is crucial and good lighting during production will save you time with much less effort than in post-production. Another tip is to use a low-compressed, intraframe codec with as high a color depth as possible. In case of YUV-type source, it is better to have subsampling $4:4:4$ or $4:2:2$.
+Here we assume that we have a good video, filmed on green or blue screen that we want to use. Important: make sure you are using a color model that has an alpha channel, such as \textit{RGBA8}, \textit{RGBAFloat}, \textit{YUVA8}. To change color model, go to \texttt{Settings $\rightarrow$ Format $\rightarrow$ Color Model}. Any manipulations with alpha masks in \CGG{} require a bottom track with some opaque background, otherwise the transparent holes are displayed as if the same track without transparency is located under it.
\subsubsection*{Usage}
\label{ssub:usage}
-As in any other effect, add it to the timeline in the main window. You can tweak each parameter in order to improve the keying.
+As in any other effect, drag it to the timeline in the main window. You can tweak each parameter in order to improve the keying.
+
+To understand how the plugin parameters work, we need to refer to the HSV color wheel (foreground color) in figure~\ref{fig:hsv_color_wheel}. You may want to first apply the \nameref{sub:color_swatch} plugin which is very helpful in determining which variables should be modified. Consider that this is an abstract example; in the real world we will be dealing with much more complicated masks.
+
+\begin{figure}[htpb]
+ \centering
+ \includegraphics[width=0.9\linewidth]{hsv_color_wheel.png}
+ \caption{Various parameters in the 'Color' and 'Key Parameters' sections.}
+ \label{fig:hsv_color_wheel}
+\end{figure}
+
+The left half has Saturation from 0 in the center to 100 on the edges. An example of a green screen is shown here. The right half has brightness from 0 (center) to 100 on the edges. The example of a blue screen is given here. The key color is the radius of the wheel, and its angle determines the hue. The Hue Tolerance is the arc of a circle (a wedge) that includes the radius. The wedge is the color range (mask) that we want to eliminate by keying, its shape is precise and easy to understand. The Brightness are the inner/outer extremes of the wedge; if the inner value (Min) is 0, then it coincides with the center point, if the outer value (max) is 100 then it coincides with the arc on the circumference. With intermediate values we will have masks similar to the one shown in the figure. Min Saturation is the distance from the center, along the Hue radius, from which we want to impose saturation with the value 0. It will be the value from which keying starts. Saturation Offset is an additional cut we make to the inner part of the wedge from the Min Saturation value. All of these adjustments allow us to establish a range of colors (Mask) that perfectly matches the background (the wedge in the example in the figure~\ref{fig:hsv_color_wheel}) that we want to eliminate. This is a precision operation, and it is not rare to return to the parameter combination several times to refine the mask.
-Start with \textit{Hue Tolerance} at $10\%$, \textit{Min Bright\-ness} at $0$, \textit{Max bright\-ness} at $100\%$, \textit{Saturation offset} at $0$, \textit{Min Saturation} at $0$, \textit{In Slope} at $0$, \textit{Out Slope} at $0$, \textit{Alpha Offset} at $0$ (that’s mid-way through), \textit{Spill Threshold} at $0$, \textit{Spill Compensation} at $100\%$. At any time, you can check what the Mask looks like by clicking on \textit{Show Mask}. This will output a black and white image of the mask (\textit{matte}).
+\qquad \textit{Color section}
+
+In this section of the configuration window, you choose the key color and have the ability to see the mask created.
+
+\begin{description}
+ \item[Color...] Select the key color (green, blue, or whatever) using the color wheel or the color picker. Only the Hue matters, not Saturation or Value. To use the color picker, click on the \textit{color picker} icon in the Compositor window, then click on the color you want in the Compositor window. Finally in the Chromakey (Avid) parameters window, click on \textit{Use Color Picker}. You will need to disable ChromaKey (Avid) plugin when using the Color Picker on the Compositor window.
+ \item[Show Mask] The plugin does not create a true matte in the alpha channel, but creates a mask. Activating this option will show the foreground as a white (opaque) shape while the background in transparency. You will be able to control the extent of the mask, any jagged edges, small white areas within the mask or small transparency areas within the foreground, which are to be removed.
+\end{description}
+
+\qquad \textit{Key parameters section}
+
+In this section we expand the mask to a range of colors close to color key and refine the selection by also taking advantage of brightness and saturation.
\begin{description}
- \item[Key color:] Select the key color (green, blue, etc) using the color wheel or the color picker. Remember, only the Hue matters, not Saturation or Value. To use the color picker, click on the \textit{color picker} icon in the Compositor window, then click on the color you want in the Compositor window. Finally in the Chromakey (HSV) parameters window, click on \textit{Use Color Picker}.
- \item[Hue Tolerance:] Because there are slight variations in lighting, the background will not be in a uniform key color hue. Increase or decrease the Hue tolerance to mask out the background. If there are dark spots that are keyed out that shouldn’t be, it can be corrected later.
- \item[Brightness:] ncrease \textit{Min Brightness} so that only the background is masked out, and not parts of the foreground. You can also reduce \textit{Max Brightness} if some clear areas are keyed out (useful for very dark backgrounds).
- \item[Saturation:] Increase \textit{Min Saturation} so that only the background is masked out, and not parts of the foreground. \textit{Saturation Offset} can be used to change this, but for now leave it set to $0$.
+ \item[Hue Tolerance:] Because there are slight variations in lighting in real cases, the background will not be in a uniform key color hue. Increase or decrease the Hue tolerance to mask out the background. In determining the hue range, it is useful to use the Color Swatch plugin in \textit{constant brightness} mode and with \textit{Draw Source} active, which allows us to see the pixels of the figure, making us choose which ones to let into the mask (keying out) and which ones not. If there are dark spots that are keyed out that shouldn’t be, it can be corrected later (With the \texttt{Mask} tool; this operation is called the \textit{Garbage Matte}).
+ \item[Brightness:] It allows the color range (Mask) to be better defined by exploiting the differences in brightness between background and foreground. This could be referred to as a Luma Key within the Chroma Key. Increase \textit{Min Brightness} so that only the background is masked out, and not parts of the foreground. You can also reduce \textit{Max Brightness} if some clear areas are keyed out (useful for very dark backgrounds).
+ \item[Saturation:] Saturation allows the color range (Mask) to be better defined by exploiting the differences in saturation between background and foreground. Since the best results are obtained by keying pure colors, it may come in handy to eliminate the less saturated colors (proper to the foreground) while leaving the more saturated colors (proper to the background, i.e. Green/Blue Screen) to the keying action. Increase \textit{Saturation Start} so that only the background is masked out, and not parts of the foreground. \textit{Saturation Line} can be used to change this, because it acts similarly to Min Brightness. It could be said that Saturation Start concerns only the key color (wedge's vertex), while Saturation Line concerns the range of Hue tolerance. But it is best to start by leaving it at $0$.
\end{description}
Check what it looks like at this stage, your mask should be pretty
clean. Toggle \textit{Show Mask} to check what it looks like, it
-should be OK\@. If not, repeat steps $1 to 4$ to get a better
+should be OK\@. If not, repeat steps in the Key parameters section to get a better
key. The rest of the controls are useful to smear the mask to help
compositing later on. They will help you to make your key look much
cleaner.
+\qquad \textit{Mask tweaking section}
+
+In this section you intervene on the already created mask with edge smoothing and transparencies.
+
\begin{description}
- \item[Slope:] For now, the mask is a full on/ full off mask that can be really harsh and not necessarily what you are looking for. \textit{In Slope} and \textit{Out Slope} will help you to smooth that key. In Slope leaves more colors in the mask, Out Slope takes more colors out of the mask. The colors that are borderline in the mask will see their alpha channel reduced by half instead of being completely on or off.
- \item[Alpha Offset] This control offsets the whole alpha channel by some amount. Be sure to know what you are doing if you change it from the default value of $0$.
- \item[spill light control:] This step helps you remove the green or blue halo around the edges of the mask. It does so by removing the saturation of pixels that have a similar hue to the key color (turning them into grey instead of green or blue). \textit{Spill Compensation} controls the amount of de-saturation. If you start with Spill Compensation at $100\%$, slowly increase the \textit{Spill Threshold} until the remaining green or blue areas turn grey. Then reduce Spill Compensation until the image looks good.
+ \item[Slope:] For now, the mask is a full on/full off mask that can be really harsh on the edges and not necessarily what you are looking for. \textit{In Slope} and \textit{Out Slope} will help you to smooth that key. In Slope acts on the inner side of the edges by grading them with keying (background) colors. It leaves more colors in the mask. Out Slope acts on the outer side of the edges by grading them with the foreground colors. It takes more colors out of the mask. Basically, the colors that are borderline in the mask will see their alpha channel reduced by half instead of being completely on or off.
+ \item[Alpha Offset:] This control offsets the whole alpha channel by some amount, from -100=full opacity to +100=full transparency. Be sure to know what you are doing if you change it from the default value of $0$.
\end{description}
-Now the mask is probably still very harsh, so just below the Chromakey (HSV) plugin, add a \textit{Blur} effect, and select only the \textit{Alpha channel}, with a radius of $2$ or $3$ (more if you really want to soften the edges). This will significantly help the keying.
+\qquad \textit{Spill light control section}
+
+In this section we try to make halos, reflections and parasitic lights present on the foreground less noticeable via spill suppression.
+
+\begin{description}
+ \item[Spill saturation:] Similar to Saturation Start, indicates the starting point from which spill suppression begins. It works if Saturation Start is > 0 because it acts only from that value, with the effect of retracting the starting point moving away from the Saturation Start value toward the center of the color wheel (white). This has the consequence of creating a small area beyond the edge of the wedge where spill suppression acts. Generally you set it with a small random value > 0 and then return to it after setting Spill Angle.
+ \item[Spill Angle:] Spill Angle is the main parameter of spill suppression because it causes a very noticeable effect. Basically, it is an area that extends beyond the edge of the mask, increasing its angle and thus its size. In this area (which is a gradient) pixels of the reflections of the key color (green, for example) are mixed with pixels of the adjacent color (cyan on one side and yellow on the other, because we always refer to the HSV color wheel). The suppression effect replaces green pixels with adjacent ones, taking into account the gradient. This parameter, in addition to the spill saturation, softens the edges of the mask without resorting to desaturation to gray or white of the green pixels, which create a more visible detachment. It should not be overdone so as not to compromise the color balance of the entire figure.
+ \item[Desature Only:] It takes the parameters of Spill Saturation and Spill Angle but instead of copying the neighboring colors over the green pixels, it applies a simple desaturation of the green pixels that become gray and then totally white. The effect is more noticeable and noisy because it creates a halo around the figure.
+\end{description}
+
+In the lower part we find various buttons:
+
+\begin{description}
+ \item[Store:] Stores the complete current parameter set in memory.
+ \item[Recall:] Sets all the parameters to the values, memorized previously by Store.
+ \item[Exchange:] Swaps current values and Store'd values of the parameters.
+ \item[Undo:] Restores all the parameters to the undo'ed values.
+ \item[Reset:] Reset to default values.
+\end{description}
+
+All buttons work globally on the whole parameter set. Each time the ChromaKey dialog is opened, the \textit{Store} values are cleared and reset to default. Therefore, if you press \textit{Recall} having not pressed Store beforehand, it will do the same as \textit{Reset}. Each time the dialog is closed, the Store values are forgotten (reset to defaults). As long as the dialog remains opened, Store values remain intact, even if the current timeline position changes. The operations on distinct parameters (turning sliders etc.) do not update the \textit{Undo} values. The following operations update values for subsequent Undo: Global Recall, Exchange, Reset buttons (but not the buttons which reset individual parameters), opening the dialog, and moving current position in the timeline.
+
+Now the mask is probably still very harsh, so just below the Chromakey (Avid) plugin, add a \textit{Blur} effect, and select only the \textit{Alpha channel}, with a radius of $2$ or $3$ (more if you really want to soften the edges). This will significantly help the keying.
+
+\subsection[Chroma Key (HSV)]{Chroma Key (HSV)}%
+\label{sub:chroma_key_hsv}
+\index{chroma key HSV}
+
+Chroma Key (HSV)\protect\footnote{Credit for Plugin by Jerome Cornet \url{http://jcornet.free.fr/linux/chromakey.html}} (figure~\ref{fig:chroma-key-hsv}) replaces a color with another color or transparency using HSV variables. This plugin is replaced by the better Chroma Key (Avid) and is maintained only for reasons of compatibility with old projects.
+Refer to Chroma Key (Avid) for theory and parameter descriptions, which are quite similar, except the description of spill suppression, which differs considerably.
+
+\begin{figure}[htpb]
+ \centering
+ \includegraphics[width=0.55\linewidth]{chroma-key-hsv.png}
+ \caption{Windows config for Chroma Key (HSV)}
+ \label{fig:chroma-key-hsv}
+\end{figure}
+
+\qquad \textit{Spill light control section}
+
+In this section we try to make halos, reflections and parasitic lights present on the foreground less noticeable.
+
+\begin{description}
+ \item[Spill light control:] This step helps you remove the green or blue halo around the edges of the mask. It does so by removing the saturation of pixels of the foreground that have a similar hue to the key color, turning them into gray instead of green or blue. The hues to be desaturated are set with \textit{Spill Threshold}, the degree of desaturation is set with \textit{Spill Compensation}. In order for Spill compensation to work, Spill Threshold must be > 0. If you start with Spill Compensation at $100\%$, slowly increase the \textit{Spill Threshold} until the remaining green or blue areas turn gray. Then reduce Spill Compensation until the image looks good.
+\end{description}
\subsection{Color 3 Way}%
\label{sub:color_3_way}
\label{fig:colorspace}
\end{figure}
+\subsection[Color Swatch]{Color Swatch}%
+\label{sub:color_swatch}
+
+Color Swatch is mainly used together with the two chroma key plugins. It should be applied first so that its output becomes the input for the chroma key.
+
+\begin{description}
+ \item[Constant Brightness:] creates the HSV color wheel in which the brightness is constant and you can only move the Brightness slider.
+ \item[Costant Saturation:] creates the HSV color wheel in which saturation is constant and you can only move the Saturation slider.
+ \item[Angle:] turns the HSV color wheel by a certain angle.
+ \item[Draw Source:] is analogous to vectorscope; shows the pixels of the upper track (figure + background = source) superimposed on the HSV color wheel. It basically displays the source colors that are also present in the color wheel, but not the others. You can easily see which colors fall within the wedge (mask) and are therefore extracted, while those outside make up the unextracted figure. This makes it easier to adjust the key color and the hue range according to our needs.
+\end{description}
\subsection{CriKey}%
\label{sub:crikey}
\label{sub:live_video}
\index{live video}
-This effect reads video directly from the capture card input. It replaces any video on the track so it is normally applied to an empty track. Only one \textit{Live Video} effect can exist at any time on the timeline. It can not be shared by more than one track. The configuration for the capture card is taken from the recording preferences. Go to \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Recording} to set up the capture card.
+This effect reads video directly from the capture card input. It replaces any video on the track so it is normally applied to an empty track. Only one \textit{Live Video} effect can exist at any time on the timeline. It can not be shared by more than one track.
+The configuration for the capture card is taken from the recording preferences. Go to \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Recording} to set up the capture card.
+There is a limitation when both Audio and Video use DV, in that you can not use this plugin at the same time as \textit{Live Audio}.
In the \textit{Video In} section where it says \textit{Record driver}, it should be set to either \textit{Video4Linux2} or \textit{IEC 61883}. Other video drivers have not been tested with Live Video and probably will not work. For live video, the selection for \textit{File} Format and \textit{Video} needs to be set to a format the timeline can use. The file format must be Quicktime for Linux and video recording must be enabled for it. Click on the wrench to set the video compression.
The video compression depends on the recording driver. For the \textit{Video4Linux2} recording driver, the compression must be \textit{Motion JPEG A}. For the \textit{IEC 61883} driver, the compression must be \textit{DV}. This gets the driver to generate output in a color model that the timeline can use. Some cards provide color and channel settings. Live video takes the color settings from the values set in the Video In window. Go to \texttt{File $\rightarrow$ Record} to bring up the recording interface and the Video In window. Values set in the Video in window are used by Live Video. Any channels the capture card supports need to be configured in the Video In interface since the same channels are used by the Live Video effect.
-With the video recording configured, highlight a horizontal region of a video track or define in and out points. Then drop the Live Video effect into it. Drop other effects after Live Video to process the live video in realtime. For best results, you should use OpenGL and a video card which supports GL shading language. Go to \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Playback $\rightarrow$ Video Out} to enable the OpenGL driver.
+With the video recording configured, highlight a horizontal region of a video track or define in and out points. Then drop the Live Video effect into it. Drop other effects after Live Video to process the live video in realtime. For best results, you should use OpenGL and a video card which supports GL shading language. Go to \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Playback $\rightarrow$ Video Out} to enable the OpenGL driver which will make it possible to process video input in real time.
\subsection{Loop video}%
\label{sub:loop_video}
\begin{description}
\item[Target Track:] you can choose between \textit{Top} and \textit{Bottom}.
- \item[Operation:] you can choose between \textit{Replace Target} (component + alpha channels); \textit{Components Only} (color channels only) and \textit{Alpha Replace} (alpha channel only)
+ \item[Operation:] you can choose between \textit{Replace Target}, \textit{Components Only} and \textit{Alpha Replace}.
+ \begin{itemize}
+ \item \textit{replace Target} (component + alpha channels), this allows you to have the ability to overwrite everything on the target track with the source track where the the plugins are inserted.
+ \item \textit{Components only} (color channels only), replace the RGB or YUV components of the target track by the RGB or YUV components of the source track. The Alpha of the target track does not change.
+ \item \textit{Alpha replace} (alpha channel only), only the Alpha of the target track is changed but the components are not. This makes it easy to create an alphs channel on a track and then use that to apply it easily to another track.
+ \end{itemize}
\end{description}
It works as a shared plugin. The typical usage scenario is to build up a possibly animated Mask in one track and then to transfer the Alpha channel to another target track.
\label{sub:swap_channels}
\index{swap channels}
-Swap R G, B, Alpha with another color channel.
+Swap color, R G B, and Alpha channels with another channel or even turn channels off completely.
\subsection{Threshold}%
\label{sub:threshold}
projects / goodguy / cin-manual-latex.git / blobdiff